Shell Programming and Scripting

Two more solutions with bc:

Code:

{ echo "m=1024;g=m*m"; sed 's/m/*m/; s/g/*g/; s/^/x+=/'; echo "x"; } < file | bc

Code:

sed 's/m/*1024/; s/g/*1048576/; s/^/x+=/; $a\
x' file | bc

I don't know why you bothered posting the following ugly approach ...
when you had this gem up your sleeve .
I was going to post a sed|bc solution along with my sed|paste|bc, but it involved accumulation in the hold space, which could hit a hold space limit or require unbounded memory. Yours cleverly leverages +=. Nicely done.

Regards,
Alister

---------- Post updated at 07:03 PM ---------- Previous update was at 06:22 PM ----------

No. Why bother wrapping sed in unnecessary echo statements?

In case you misinterpreted my intent, my post's disparagement of your first solution was only intended as a lighthearted setup for my appreciation of the cleverness of your second solution.

Regards,
Alister

Code:

{ echo "m=1024;g=m*m"; sed 's/m/*m/; s/g/*g/; s/^/x+=/'; echo "x"; } < file | bc

This code also looks like having lot of ; ..,instead of pipe. May take longer time for execution.

Code:

sed 's/m/*1024/; s/g/*1048576/; s/^/x+=/; $a\
x' file | bc

But the next code looks ok, why it is written in two lines. Thanks a lot..

---------- Post updated at 10:29 PM ---------- Previous update was at 10:23 PM ----------

Best so far this one, with yoda's awk's quick execution , but not sure how paste command in this would react for longer lines say 500000 ines +:

Code:

cat file|sed 's/m/*1024/; s/g/*1048576/' | paste -sd+ - | bc